Maneka Gandhi Column

By Maneka Gandhi

Fish are more intelligent than they appear. In many areas, such as memory, their cognitive powers match or exceed those of ‘higher’ vertebrates including non-human primates. Dolphins for example have been declared the world’s second most intelligent creatures after humans, with scientists suggesting they are so bright that they should be treated as “non-human persons”.

Studies into dolphin behavior have highlighted how similar their communications are to those of humans and that they are brighter than chimpanzees. These have been backed up by anatomical research showing that dolphin brains have many key features associated with high intelligence.

Dolphins have distinct personalities, a strong sense of self and can think about the future. It has also become clear that they are “cultural” animals, meaning that new types of behavior can quickly be picked up by one dolphin from another.

In one study, Diana Reiss, professor of psychology at Hunter College, City University of New York, showed that bottlenose dolphins could recognize themselves in a mirror and use it to inspect various parts of their bodies, an ability that had been thought limited to humans and great apes.

Other research has shown dolphins can solve difficult problems, while those living in the wild co-operate in ways that imply complex social structures and a high level of emotional sophistication.

In one recent case, a dolphin rescued from the wild was taught to tail-walk while recuperating for three weeks in a dolphinarium in Australia. After she was released, scientists were astonished to see the trick spreading among wild dolphins who had learnt it from the former captive.

Being underwater, the fish’s basic “intelligence” and sensory skills are adapted very differently from the land-based animals. The animals’ primary concerns are, fundamentally, to eat and not be eaten. Aquatic dwellers also employ their senses mainly for self-preservation and the propagation of the species.

Some researchers suggest these fish might have an unusually sophisticated social learning capability not yet found in other animals, called a ‘hill-climbing’ strategy.

The ability of picking the best quality food patch by comparing how successful others are at getting food from it against their personal experience has not been shown before in animals.

Fish sense hunger, pain, and threat. They become aggressive when biological triggers signal the craving for food, or the need to defend a brood or a territory. Fish also communicate with one another, and may even try to communicate with you.

Paradise fish for example can avoid places where they have experienced a single attack by a predator and continue to do so for many months. Also, several fish species are capable of learning complex spatial relationships and forming mental maps and integrate experiences which enable the fish to generate appropriate avoidance responses.

It is known that some cichlids can recognize the world outside their tank, and may follow fingers across the glass, etc. The red parrot fish, in particular, has been reported to be trained to eat out of the owner’s hands. It has a reputation for “intelligence,” “personality,” and the ability to adapt. Fish can sense the smallest vibrations through the water, tapping the aquarium tank, the stand that holds it.

As for color vision, research has confirmed that fish can see color, to some extent, above and beyond some practical uses of color. For example, the fact that most strikingly colored species use their pigmentation to attract mates; or use color to hide from and ward off predators.

Fish intelligence is helping humans nowadays. Most hydro-power turbines require water to be flowing at a 5-knot minimum. But now, scientists are borrowing from fish to create energy in slow-moving water.

Hydropower researchers at the University of Michigan are borrowing strategies from fish to maximize the energy that can be harvested from slow-moving water. For example, trout use spinning eddies that form on both sides of a stationary object, like a rock, to help conserve energy as they swim upstream. The vortexes that form alternate from one side of the rock to the other, so fish swimming upstream slalom between these whirlpools. Schools also use vortexes created by the fish ahead to conserve energy when swimming upstream.

*To join the animal welfare movement contact the author at gandhim@nic.in

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